Episode 73 | Avalanche Awareness for Backpackers

Avoiding terrain capable of producing an avalanche weighs nothing. Understanding weather, snowpack, terrain, and human factors that lead to avy hazards weighs nothing.

But if you need to expose yourself to avy hazards, anything short of carrying a transceiver, probe, and shovel (and being darn handy with them) is not being responsible. That goes for you and everyone in your group. Pieps makes a very small and light transceiver (Micro BC), BCA makes a very light carbon probe (Stealth 260), and Arva makes a very light avy shovel (Ultra). I would only resort to such light gear if avy exposure was truly minimal and yet unavoidable.

If you are going solo you can skip all that stuff because no one is there to help you and you won’t need to assist anyone else. If solo, wearing a transceiver could be considered polite towards would-be SAR resources because it speeds up body recovery immensely.

Oh, and another thing not many people think of, is the risk of falling rock in winter, which is worse when a bad rock face freezes and thaws a number of times, letting rock come loose. Even if the snow looks solid, the rock above might have a higher chance of coming down if there is a melt and freeze cycle. This is pretty common here in the Olympic Mountains due to the rotten rock everywhere.

As a former alpine ski patroller in an avalanche-prone resort where a 105 mm Howitzer is used routinely all patrollers had to attend and pass the Avalanche 1 course, practice line probing with poles and finding and digging out a buried avalanche beacon in the newer “rotating shovelers” pattern with a V pattern of excavation.

If you backpack in avalanche danger areas, aside from Avalanche 1 training, you need:

1.)avy beacons (all turned to “transmit”) 2.)collapsable shovels  3.)probe poles/convertible hiking poles

4.)snow study kit (one per group)  5.)SATELLITE RESCUE BEACONS (several, in case one gets buried with a hiker)

Sounds like a lot of “bother” – until you need all of this training and gear, then it’s life saving.

BTW, having a woman in a hiking/skiing group seems to limit the “macho quotient” of a group where otherwise prudent people in an all male group may be quiet when the more macho men literally intimidate them into taking a risky route. MORAL: Take a few women in your group into avy terrain.

For runout zones, you should discuss what is called “alpha angle”.  It’s basically the angle, from horizontal, between where you are standing/ walking/ camping, and possible avalanche start zones above you (corniced ridge, change in slope angle, etc).  It’s a measure of how far an avalanche could potentially run from that slide path before stopping.
Unfortunately, the critical alpha angle is different for every region, because the snow types are different. It’s important to know what the critical alpha angle is for the region you are in, so you can be sure to stay out of runout zones.
For example, we recently had a very large avalanche here in Utah where I live that traveled 12.8° from the initiation point.

Bryan, that sounds like the big slide on Gobblers know recently which ran an extraordinarily long distance on low angle terrain after propagating on steeper terrain. Scary stuff. Luckily it wasn’t human triggered and no one was there.

I’d say the 1st most important thing to learn is terrain avoidance. Learning safe corridors to travel and how to spot terrain traps is crucial 1st steps. Visability is key here and knowing what is above you as well.  proper avalanche search techniques are equally important but with terrain aviodance, someone with limited avalanche experience could still get out and enjoy winter travel. Once some knowledge is gained thru avalanche courses on evaluating snow should one consider going into avalanche terrain.

Ryan, to your point of staying below tree line, I would say that is a complicated issue. Lots of avalanches have started and/or run thru heavily tree’d areas.

Ryan – sorry, I honestly mis-remembered the alpha angle on that slide and couldn’t find it to look it up. It was actually 17.2deg. 6-8’ deep, so pretty scary. Here’s the write-up.
https://utahavalanchecenter.org/avalanche/73452

Thank you for covering this concept in the related Member Q&A.